Lithium-ion (Li-ion) batteries have been widely used for portable electronics, and they are being intensively pursued for hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), electric vehicles (EVs), and stationary power source applications for smarter energy management systems. The greatest challenges in adopting the technology for large-scale applications are the energy density, power density, cost, safety and cycle life of current electrode materials. Energy density as well as the capacity of both anode and cathode is the most important factor for the energy storage systems. The state of the art portable electronics devices, like smart phone which has quad-core processor, 4 GB RAM, 20 mega pixels camera and 4G wireless communication capability, but the battery can only last for one day. It is also the same for the electric vehicles; most cars could have a limited cursing range after a single charge. On the other hands, the charging time as well as the power density is another important characteristic for the battery, especially as the application targets of Li-ion batteries move from small mobile devices to transportation. This is because electrical vehicle (EV) users are hardly to wait more than half an hour to charge their vehicles compared with a refueling period of less than 5 minutes for gasoline cars. The speed of charge greatly depends on the lithiation rate capability of anode materials.
At present, graphite is the most popular and practical anode material for Li-ion batteries because of its low cost, relatively long cycle life, and ease of processing. However, the relative small capacity (<372 mAh/g) and poor rate capability limited their application in high energy and power energy storage systems. CN103708437 and U.S. Pat. No. 8,691,442 are using amorphous carbon based materials such as soft carbon and hard carbon usually have larger interlayer spaces than graphite, offering a faster lithium input rate than graphite. However, soft carbon usually has an even smaller capacity (around 250 mAh/g) than graphite and higher average potential while charging and discharging; it is difficult to be used in Li-ion batteries with high energy density. Hard carbon has a capacity around 400 mAh/g, but its low density, low coulombic efficiency, and high cost, which make it difficult to use in batteries for EVs and plug-in hybrid vehicles (PHVs) at a low enough cost. Other high capacity anode materials, proposed in WO2013/142287, US2012/0129054, WO2008/139157, US2010/0190061, WO2014/083135, CN101914703 and U.S. Pat. No. 7,687,201, are using silicon or tin that is capable of forming an alloy with lithium. However, such an element has even worse lithiation rate capability because of the low kinetics of lithium alloying and the accessibility of lithium ion through thick solid-electrolyte interface (SEI). There are some attempts such as JP2014-130821A, JP2001-302225A and JPH10-188958A, in which some additional elements such as boron are added to increase the capacity of the carbon materials.